I'm investigating an alternative form of 4-way tilt switch which I cooked up, for similar reasons - existing ones are expensive and were not in my hands at the time. It's based on a UK Penny (which has copper outer) some stripboard and header pins but I guess it would work with any clean metal coin. There's a video intro here...

I'm expecting to do some interpolation and a circular buffer to handle the fact that the contact with the coin is transient, at each extreme of the POV sweep. Ideally I'll be creating an X-shaped LED array so that a POV baby shaker can be created which writes in any direction it's shaken.